The present invention relates generally to new and novel kingpin security devices. More particularly, the present invention relates to kingpin security devices which engage a portion of a kingpin extending from a trailer and, when so engaged, prevent a tractor from hitching onto the trailer.
Semi-tractors which pull loaded trailers are a prime means of transporting items from one location to another. A large trailer can be loaded and unloaded, and hitched to a motorized tractor. It is common for a single tractor to pull several different trailers. For example, a tractor may pull a trailer containing raw materials to a factory. The trailer can be unhitched and stored until the materials are needed. Meanwhile, the tractor may be hitched to another trailer which contains a finished product. The tractor may haul these items to a distribution center, where they can be distributed to several different outlets. The tractor may then be used to haul yet another trailer to one of these outlets. Thus, the ability of the tractor to engage and haul various trailers is crucial.
To meet this need, the transportation industry has established certain design standards. These include standardizing the dimensions and placement of the hitching mechanisms found on both tractors and trailers. A standard trailer includes a kingpin which extends downwardly from beneath the trailer. The kingpin is a generally cylindrical member and is located near the front end of the trailer. The kingpin includes an annular recess which forms an annular lip at its distal end. Each tractor has a hitching means which accepts the kingpin. The tractor can be backed up to the front of the trailer, until the kingpin is received by the hitching means located on the tractor. The dimensions and location of the kingpin on the trailer, and the design of the hitching means located on the tractor are governed by industry standards. This ensures the interchangeability of tractors and trailers, which is a necessity in the trucking industry. This same kingpin attachment arrangement is also widely utilized on so-called "fifth wheel" recreational vehicles to connect the trailer to the pick-up truck or other vehicle for hauling.
However, due to standardization, it is relatively easy for vandals or those with unauthorized access to a trailer to hitch the trailer to a tractor and steal the trailer and its contents. Any person having a tractor with a standard hitching mechanism may back up to and engage any trailer with a standardized kingpin. Loaded trailers are often stored for short periods of time in warehouse parking lots, and thus make easy prey for the unscrupulous. Therefore, there is a great need for economical and effective security devices which prohibit unauthorized engagement of a tractor to a trailer.
Several mechanisms have been devised to protect a trailer kingpin from unauthorized engagement to a tractor. Generally, these devices can be grouped into two categories. The first type of kingpin locking device generally utilizes a hollow, cylindrical sleeve which circumferentially encases a portion of the kingpin. A locking cam is then actuated so as to engage a portion of the annular recess on the kingpin. The cam member can then be locked into position to prevent removal of the locking device. This is commonly accomplished using an ordinary padlock or similar locking mechanism. However, ordinary padlocks can be easily removed by vandals, using heavy-duty bolt cutters or the like. Thus, it is preferable to utilize a locking mechanism which is not accessible by conventional tools.
With this in mind, many of the prior art locking devices of the first type enclose the locking mechanism within the sleeve. Such devices are shown in U.S. Pat. No. 4,553,415 to Maffey and U.S. Pat. No. 4,841,756 to Curtis. U.S. Pat. No. 3,415,085 to Eble, Jr. shows a locking device with an external plate attached to the sleeve which obstructs access to the padlock.
The second type of kingpin security mechanism generally includes devices comprising two wing members which are hingeably attached. The two wing members are pivoted about the hinge to surround the kingpin. The free ends of the two wing members are then locked together, using a conventional padlock or similar device. Such devices are shown in U.S. Pat. No. 2,785,564 to Rossi and U.S. Pat. No. 4,141,233 to Reyes.
The known prior art kingpin security mechanisms have several disadvantages. First, many of the prior art kingpin security devices are cumbersome to use and difficult to attach to a kingpin. To effectively prevent unauthorized use of the trailer, kingpin locking mechanisms must be durable, and are usually fabricated from cast iron or steel. Thus, the kingpin security device itself is often large and heavy, and difficult to handle. Thus, to attach a kingpin security device to a kingpin, the user must crawl or reach under the trailer and lift the kingpin security device over the kingpin. This is a difficult procedure when using many of the heavy and cumbersome prior art kingpin security devices.
Attaching these prior art kingpin security devices to the kingpin is further complicated in that the user must generally hold the device over the kingpin while activating the lock. Thus, while crawling or reaching underneath the trailer, the user must position the heavy and cumbersome kingpin security device over the kingpin with one hand, and position and activate the lock with the other hand. This is not always an easy task.
Another limitation of the known kingpin security mechanisms is that they often do not provide protection for the padlock or other locking device. As seen in the '564 patent to Rossi and the '233 patent to Reyes, the shackles of the engaged padlock are exposed. Vandals using bolt cutters could easily cut through the lock shackles and remove these kingpin security devices from the kingpin. Some of the sleeve type kingpin security devices have attempted to solve this problem by enclosing the locking device within the kingpin security device itself. However, doing so typically adds to the cost, weight and complexity of the kingpin security mechanism.
Many known security mechanisms are also limited in their ability to withstand substantial force. If a tractor would attempt to engage a trailer which has many of the currently known kingpin security devices engaged to it, the force exerted by the hitching mechanism will often cause deformation of the security device. Such deformation can preclude the kingpin security mechanism from further use. More importantly, it may be difficult to remove a severely deformed kingpin security device from the kingpin. Because a close tolerance fit about the kingpin is necessary for many kingpin security devices, relatively small deformations may prohibit normal removal of the kingpin security device from the kingpin. If normal removal is not possible, a torch or similar device may be required to remove the deformed kingpin security device from the kingpin.
Accordingly, an object of the present invention is the provision of a kingpin security mechanism which does not experience excessive deformation from normal forces.
Another object of the present invention is to provide a kingpin security mechanism which is relatively compact and lightweight, and which can be easily handled, installed and removed by a user.
A further object of the present invention is to provide a kingpin security mechanism which slidably engages a portion of a trailer kingpin, and which does not need to be held in place while a conventional padlock or similar locking device is attached thereto.
Yet another object of the present invention is to provide a kingpin security mechanism which shields the shackles of the padlock from vandals using conventional tools.
A still further object of the present invention is to provide a kingpin security mechanism which is economical to manufacture.
Yet another object of the present invention is to provide a kingpin security mechanism which slidably engages a portion of the annular lip of the kingpin.
These and other objects of the present invention are attained by the provision of a kingpin security device preferably fabricated from ductile iron. The kingpin security device preferably comprises a base having a generally flat top surface and a plate which extends vertically upwardly from the top surface. In some preferred embodiments, the base has a generally semi-circular cross-section and includes a channel adjacent the top surface of the base. In other preferred embodiments, the base has an interrupted semi-circular cross-section and includes a channel adjacent to the top surface of the base. The channel engages with the annular lip of the kingpin, and the upwardly extending plate engages with a portion of the annular recess of the kingpin.
Opposite the upwardly extending plate, the base includes a horizontally extending arm portion. A standard padlock is attached to the kingpin security device such that the shackles of the lock go around the arm. The bight of the shackles engage the annular lip of the kingpin at a point opposite its engagement within the channel. This secures and prevents disengagement of the kingpin from the kingpin security device. Attached to the distal end of the arm portion is a shield plate. The base is further provided a flange extending upwardly from the base. The downwardly extending flange and the shield plate are spaced such that the shackles and body of the padlock are positioned therebetween, but access to the shackles by conventional tools is precluded. A reinforcing rib preferably extends from the bottom surface of the base to the flange, and provides additional structural support for the kingpin security device.
Other objects, advantages and novel features of the present invention will become apparent in the following detailed description of the invention when considered in conjunction with the accompanying drawings.